Hot melt adhesive for infant navel stickers, method of preparing the same, and infant navel sticker comprising the same

Abstract

The application provides a hot melt adhesive for infant umbilical sticking plaster and a preparation method thereof and an infant umbilical sticking plaster containing the same, and relates to the technical field of medical devices. The hot melt adhesive for infant umbilical sticking plaster is mainly composed of a thermoplastic copolymer, mineral oil, tackifying resin, cellulose, anti-inflammatory substances and antioxidants, wherein the mass ratio of the thermoplastic copolymer, the tackifying resin and the cellulose is 10-20:20-30:20-50. The applicant finds, through long-term experimental research, that the hot melt adhesive obtained from the mass ratio of the thermoplastic copolymer, the tackifying resin and the cellulose has good sticking viscosity and appropriate peeling force under the condition of 35-40 DEG C, and the use of the hot melt adhesive as the infant umbilical sticking plaster can achieve the technical effects of good sticking, painless and easy tearing. Meanwhile, the hot melt adhesive contains anti-inflammatory substances, and all the raw materials used are non-allergic and non-irritating, so that the hot melt adhesive for infant umbilical sticking plaster also has good anti-inflammatory and anti-allergic effects.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a hot melt adhesive for infant umbilical cord dressing, a method for preparing the same, and an infant umbilical cord dressing containing the same. Background Technology

[0002] After a newborn's umbilical cord is cut, an infant umbilical patch is often used to prevent infection. In long-term clinical practice, doctors have found that after applying the patch to a child's abdomen with medical tape, the patch is easily rubbed off due to the child's frequent movements. Furthermore, existing umbilical patches often contain adhesive components such as rubber, which can cause allergic reactions in infants with delicate skin, leading to redness, swelling, and inflammation of the navel. Additionally, the anti-inflammatory medications in existing umbilical patches may gradually evaporate and become ineffective over prolonged use.

[0003] Therefore, it is both necessary and urgent to research and develop an infant umbilical patch that is easy to apply, painless, and easy to tear at body temperature (35-40℃), and has excellent anti-inflammatory and anti-allergic effects.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] The first objective of this invention is to provide a hot melt adhesive for infant umbilical cord patches, which has good adhesion and appropriate peel strength at 35-40°C, and its use as a hot melt adhesive for infant umbilical cord patches can achieve the technical effects of good adhesion, painless and easy peeling.

[0006] A second objective of this invention is to provide a method for preparing a hot melt adhesive for an infant umbilical cord patch.

[0007] A third objective of the present invention is to provide an infant umbilical patch, wherein the sol layer of the infant umbilical patch is mainly prepared from the hot melt adhesive used for infant umbilical patches described above.

[0008] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:

[0009] This invention provides a hot melt adhesive for infant umbilical cord patches, wherein the hot melt adhesive is mainly prepared from thermoplastic copolymers, mineral oil, tackifying resins, cellulose, anti-inflammatory substances, and antioxidants, wherein:

[0010] The mass ratio of the thermoplastic copolymer, tackifying resin, and cellulose is 10–20: 20–30: 20–50.

[0011] Furthermore, the thermoplastic copolymer is at least one of styrene-isoprene block copolymer (SIS), styrene-butadiene block copolymer (SBS), hydrogenated styrene-isoprene block copolymer (SEPS), and hydrogenated styrene-butadiene block copolymer (SEBS).

[0012] Preferably, the thermoplastic copolymer is obtained by compounding styrene-isoprene block copolymer (SIS) and hydrogenated styrene-butadiene block copolymer (SEBS), wherein the weight ratio of styrene-isoprene block copolymer (SIS) to hydrogenated styrene-butadiene block copolymer is 10 to 15:5.

[0013] Furthermore, the tackifying resin is at least one of rosin resin, hydrogenated rosin resin, C5 petroleum resin, C9 petroleum resin, and C5 / C9 copolymer resin, preferably C5 or C9 petroleum resin.

[0014] Furthermore, the cellulose is at least one of methylcellulose (MC), hydroxypropyl methylcellulose (HPMC), hydroxyethyl cellulose (HEC), and carboxymethyl cellulose (CMC).

[0015] Furthermore, the anti-inflammatory substance is an ionic bactericide;

[0016] The ionic bactericide includes silver ion bactericide, copper ion bactericide and zinc ion bactericide, preferably silver-loaded zirconium phosphate inorganic antibacterial powder.

[0017] Furthermore, the mineral oil is a naphthenic oil or white mineral oil;

[0018] The antioxidant is a sterically hindered phenolic antioxidant, which is one or two of BASF's antioxidant rganox B225 and 2,6-di-tert-butyl-4-methylphenol.

[0019] Furthermore, by weight, the hot melt adhesive comprises:

[0020] 10-20 parts thermoplastic copolymer, 5-10 parts mineral oil, 20-30 parts tackifying resin, 20-50 parts cellulose, 1-10 parts anti-inflammatory substance, and 0.1-0.5 parts antioxidant.

[0021] The present invention provides a method for preparing the above-mentioned hot melt adhesive for infant umbilical cord patches, the method comprising:

[0022] (A) A portion of the tackifying resin is heated and melted with mineral oil and antioxidants and mixed to obtain intermediate A;

[0023] (B) Add the thermoplastic copolymer to intermediate A and heat and stir until melted. Then add the remaining tackifying resin and heat and stir until melted. Then add cellulose and anti-inflammatory substances and heat and stir until melted to obtain intermediate B.

[0024] (C) Cool intermediate B to obtain hot melt adhesive for infant umbilical cord patch;

[0025] The heating and melting temperature of steps (A) and (B) in the preparation process is 140-145℃.

[0026] Furthermore, the tackifying resin in step (A) is 40% of the total mass of the tackifying resin;

[0027] The tackifying resin added in step (B) is 60% of the total mass of the tackifying resin;

[0028] Step (B) is carried out under negative pressure evacuation conditions.

[0029] The present invention provides an infant umbilical patch, which includes a backing layer and a sol layer; the sol layer is mainly prepared from the hot melt adhesive used for infant umbilical patches described above.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0031] The hot melt adhesive for infant umbilical cord patches provided by this invention is mainly prepared from thermoplastic copolymers, mineral oil, tackifying resins, cellulose, anti-inflammatory substances, and antioxidants, wherein the mass ratio of the thermoplastic copolymer, tackifying resin, and cellulose is 10-20:20-30:20-50. Through long-term experimental research, the applicant has found that the hot melt adhesive prepared from the above-mentioned mass ratio of thermoplastic copolymer, tackifying resin, and cellulose exhibits excellent adhesion and appropriate peel strength at 35-40°C. Using it as a hot melt adhesive for infant umbilical cord patches achieves the technical effects of good adhesion, painless application, and easy removal. Furthermore, the hot melt adhesive of this application also contains anti-inflammatory substances, and all raw materials used are non-allergenic and non-irritating. Therefore, the hot melt adhesive for infant umbilical cord patches of this application also has excellent anti-inflammatory and anti-allergic effects.

[0032] The present invention provides a method for preparing hot melt adhesive for infant umbilical cord patches. This method involves first heating and melting a portion of the tackifying resin with mineral oil and an antioxidant until homogeneous; then adding a thermoplastic copolymer, the remaining tackifying resin, cellulose, and an anti-inflammatory substance. This step-by-step preparation method effectively improves the compatibility of the components in the hot melt adhesive, resulting in a hot melt adhesive for infant umbilical cord patches with excellent stability. Furthermore, the preparation method of this application has the advantages of simple operation and ease of scaling up production.

[0033] The umbilical cord patch provided by this invention has an adhesive layer mainly prepared from the hot melt adhesive used for umbilical cord patches as described above. Due to the properties of the hot melt adhesive used for umbilical cord patches, this umbilical cord patch has good adhesion, is painless and easy to peel off at 35-40°C, and has excellent anti-inflammatory and anti-allergic effects. Detailed Implementation

[0034] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] According to one aspect of the present invention, a hot melt adhesive for an infant umbilical cord patch, said hot melt adhesive being prepared mainly from a thermoplastic copolymer, mineral oil, tackifying resin, cellulose, anti-inflammatory substances, and antioxidants, wherein:

[0036] The mass ratio of the thermoplastic copolymer, tackifying resin, and cellulose is 10–20: 20–30: 20–50.

[0037] The hot melt adhesive for infant umbilical cord patches provided by this invention is mainly prepared from thermoplastic copolymers, mineral oil, tackifying resins, cellulose, anti-inflammatory substances, and antioxidants, wherein the mass ratio of the thermoplastic copolymer, tackifying resin, and cellulose is 10-20:20-30:20-50. Through long-term experimental research, the applicant has found that the hot melt adhesive prepared from the above-mentioned mass ratio of thermoplastic copolymer, tackifying resin, and cellulose exhibits excellent adhesion and appropriate peel strength at 35-40°C. Using it as a hot melt adhesive for infant umbilical cord patches achieves the technical effects of good adhesion, painless application, and easy removal. Furthermore, the hot melt adhesive of this application also contains anti-inflammatory substances, and all raw materials used are non-allergenic and non-irritating. Therefore, the hot melt adhesive for infant umbilical cord patches of this application also has excellent anti-inflammatory and anti-allergic effects.

[0038] In a preferred embodiment of the present invention, the thermoplastic copolymer is at least one of styrene-isoprene block copolymer (SIS), styrene-butadiene block copolymer (SBS), hydrogenated styrene-isoprene block copolymer (SEPS), and hydrogenated styrene-butadiene block copolymer (SEBS).

[0039] In the preferred embodiment described above, the thermoplastic copolymer is obtained by compounding styrene-isoprene block copolymer (SIS) and hydrogenated styrene-butadiene block copolymer (SEBS), wherein the weight ratio of styrene-isoprene block copolymer (SIS) to hydrogenated styrene-butadiene block copolymer (SEBS) is 10 to 15:5.

[0040] As a preferred embodiment, the hot melt adhesive for infant umbilical patches prepared by this application is prepared using a thermoplastic copolymer obtained by compounding the above-mentioned SIS and SEBS in a weight ratio of 10 to 15:5. It has good fit, good sweat resistance, and antibacterial and anti-inflammatory effects.

[0041] In a preferred embodiment of the present invention, the tackifying resin is at least one of rosin resin, hydrogenated rosin resin, C5 petroleum resin, C9 petroleum resin, and C5 / C9 copolymer resin, preferably C5 or C9 petroleum resin.

[0042] As a preferred embodiment, this application uses C5 or C9 petroleum resin as the tackifying resin, which is non-irritating to the skin, and the hot melt adhesive for infant umbilical patches prepared using it has a good skin-friendly effect.

[0043] In a preferred embodiment of the present invention, the cellulose is at least one of methylcellulose (MC), hydroxypropyl methylcellulose (HPMC), hydroxyethyl cellulose (HEC), and carboxymethyl cellulose (CMC).

[0044] In a preferred embodiment of the present invention, the anti-inflammatory substance is an ionic bactericide;

[0045] The ionic bactericide includes silver ion bactericide, copper ion bactericide and zinc ion bactericide, preferably silver-loaded zirconium phosphate inorganic antibacterial powder.

[0046] As a preferred embodiment, the zinc phosphate silver-loaded inorganic antibacterial powder used in this application has the technical effect of high temperature resistance, and can withstand high temperatures of 1300℃, which is more conducive to the preparation of hot melt adhesive for infant umbilical patches compared with existing antibacterial drugs.

[0047] The preparation method of the zirconium phosphate silver-loaded inorganic antibacterial powder is as follows: zirconium phosphate is prepared into nano-level zirconium phosphate silver-loaded inorganic antibacterial powder under acidic conditions by ion exchange method, and the crystal particle size is controlled by ethylene glycol and polyethylene glycol; then, the finished product of zirconium phosphate silver-loaded inorganic antibacterial powder with a certain moisture content and uniform morphology is obtained by baking. The prepared zirconium phosphate silver-loaded inorganic antibacterial powder has the characteristics of strong antibacterial ability and excellent stability at high temperature.

[0048] Preferably, the zinc phosphate silver-loaded inorganic antibacterial powder of this application is prepared using the preparation method in Example 1 of CN100345486C.

[0049] In a preferred embodiment of the present invention, the mineral oil is naphthenic oil or white mineral oil;

[0050] The antioxidant is a sterically hindered phenolic antioxidant, which is one or two of BASF's antioxidant rganox B225 and 2,6-di-tert-butyl-4-methylphenol.

[0051] In a preferred embodiment of the present invention, the hot melt adhesive comprises, by weight parts:

[0052] 10-20 parts thermoplastic copolymer, 5-10 parts mineral oil, 20-30 parts tackifying resin, 20-50 parts cellulose, 1-10 parts anti-inflammatory substance, and 0.1-0.5 parts antioxidant.

[0053] According to one aspect of the present invention, a method for preparing the above-mentioned hot melt adhesive for infant umbilical cord patches, the method comprising:

[0054] (A) A portion of the tackifying resin is heated and melted with mineral oil and antioxidants and mixed to obtain intermediate A;

[0055] (B) Add the thermoplastic copolymer to intermediate A and heat and stir until melted. Then add the remaining tackifying resin and heat and stir until melted. Then add cellulose and anti-inflammatory substances and heat and stir until melted to obtain intermediate B.

[0056] (C) Cool intermediate B to obtain hot melt adhesive for infant umbilical cord patch;

[0057] The heating and melting temperature of steps (A) and (B) in the preparation process is 140-145℃.

[0058] The present invention provides a method for preparing hot melt adhesive for infant umbilical cord patches. This method involves first heating and melting a portion of the tackifying resin with mineral oil and an antioxidant until homogeneous; then adding a thermoplastic copolymer, the remaining tackifying resin, cellulose, and an anti-inflammatory substance. This step-by-step preparation method effectively improves the compatibility of the components in the hot melt adhesive, resulting in a hot melt adhesive for infant umbilical cord patches with excellent stability. Furthermore, the preparation method of this application has the advantages of simple operation and ease of scaling up production.

[0059] In a preferred embodiment of the present invention, the tackifying resin in step (A) is 40% of the total mass of the tackifying resin; and the tackifying resin added in step (B) is 60% of the total mass of the tackifying resin.

[0060] In a preferred embodiment of the present invention, step (B) is performed under negative pressure evacuation conditions.

[0061] As a preferred embodiment, step (B) is carried out under negative pressure vacuum conditions, which helps to increase the probability that each component does not contain unsaturated bonds, thereby improving the bonding performance and weather resistance of the obtained hot melt adhesive.

[0062] According to one aspect of the present invention, an infant umbilical patch includes a backing layer and a sol layer; the sol layer is mainly prepared from the above-mentioned hot melt adhesive for infant umbilical patches.

[0063] The umbilical cord patch provided by this invention has an adhesive layer mainly prepared from the hot melt adhesive used for umbilical cord patches as described above. Due to the properties of the hot melt adhesive used for umbilical cord patches, this umbilical cord patch has good adhesion, is painless and easy to peel off at 35-40°C, and has excellent anti-inflammatory and anti-allergic effects.

[0064] The technical solution of the present invention will be further described below with reference to the embodiments.

[0065] Note: The specifications, models, and manufacturers of the raw materials used in the following examples / comparative examples are as follows:

[0066]

[0067]

[0068] Examples 1-3

[0069] A method for preparing hot melt adhesive for infant umbilical cord patches, wherein the raw materials for the hot melt adhesive include:

[0070]

[0071] The preparation method includes:

[0072] 1) Add mineral oil, 40% of the total weight of tackifying resin, and antioxidant to the reactor, and control the temperature at 140-145℃ to melt the tackifying resin.

[0073] 2) After the tackifying resin in step 1) has completely melted, add the thermoplastic copolymer, control the stirring speed to 15-20 r / min and the pressure to -0.8-1 MPa and degas for 80-100 min until the thermoplastic copolymer has completely melted;

[0074] 3) Add the remaining tackifying resin, control the temperature at 140-145℃, the rotation speed at 60-80 r / min, and the pressure at -1.0--0.9 MPa, and perform evacuation for 30-40 minutes;

[0075] 4) After the tackifying resin in step 3) has completely melted, add cellulose and anti-inflammatory substances. Control the stirring speed to 15-20 r / min and the pressure to -0.8-1 MPa and degas for 20-30 minutes until the cellulose and anti-inflammatory substances are evenly dispersed. Then let it cool naturally to room temperature to obtain a hot melt adhesive for an infant umbilical patch.

[0076] Example 4

[0077] This embodiment is the same as embodiment 2 except that “C5 petroleum resin” is replaced with “rosin resin”.

[0078] Subsequent application tests revealed that the tackifying resin used in this embodiment is rosin resin. Since rosin resin has a certain degree of skin irritation, after the umbilical patch made from the hot melt adhesive of this embodiment was applied to the skin of an adult's palm for 24 hours, a certain degree of redness appeared on the skin surface. However, the umbilical patch made from the hot melt adhesive of Embodiment 2 of this application did not produce the above phenomenon in the test.

[0079] Example 5

[0080] This embodiment is the same as in Embodiment 2, except that "zirconium phosphate silver-loaded inorganic antibacterial powder" is replaced with "inorganic silver ions".

[0081] Comparative Examples 1-6

[0082] A method for preparing hot melt adhesive for infant umbilical cord patches, wherein the raw materials for the hot melt adhesive include:

[0083]

[0084]

[0085] The preparation method is the same as in Example 2.

[0086] Experimental Example 1

[0087] To demonstrate that the hot melt adhesive used in this application for infant umbilical cord patches has good adhesion and appropriate peel strength at 35-40°C, the adhesion properties of the hot melt adhesives for infant umbilical cord patches prepared in Examples 1-5 and Comparative Examples 1-6 were tested.

[0088] The specific testing methods are as follows:

[0089] The samples prepared in Examples 1-5 and Comparative Examples 1-6 were distributed to laboratory personnel for patch efficacy testing. The patching sites were inflamed areas, and the results of each experiment were statistically analyzed 24 hours after application.

[0090] The specific test results are as follows:

[0091]

[0092]

[0093] The test results above show that the hot melt adhesive for infant umbilical patches prepared in Examples 1-4 has good adhesion and appropriate peel force at 35-40℃. Further preparation of these adhesives into infant umbilical patches can achieve the technical effects of good adhesion, painless application, and easy peeling. However, Example 4 contains a relatively high amount of rosin, thus posing a significant risk of allergic reactions.

[0094] The zirconium phosphate silver-loaded inorganic antibacterial powders in Examples 1-4 exhibit better temperature resistance and stability compared to the product prepared using inorganic silver ions in Example 5. Furthermore, the zirconium phosphate silver-loaded inorganic antibacterial powder does not affect the product's inherent performance during high-temperature preparation. While the adhesive viscosity and peel strength of the hot melt adhesive used in the infant umbilical patch prepared in Example 5 were moderate, the anti-inflammatory effect of the inorganic silver did not meet requirements after high-temperature processing.

[0095] In the embodiments of Comparative Examples 1-6 where the mass ratio of thermoplastic copolymer, tackifying resin, and cellulose was not in the range of 10-20:20-30:20-50, the adhesion viscosity and peel strength at 35-40°C were not ideal, as detailed below:

[0096] In Comparative Example 1, the mass ratio of thermoplastic copolymer, tackifying resin, and cellulose was 5:20:20. Due to the low content of thermoplastic copolymer in the ratio, the product prepared by applying it to the umbilical patch was hard and had poor adhesion. However, the peel strength was too high, which caused greater pain.

[0097] In Comparative Example 2, the mass ratio of thermoplastic copolymer, tackifying resin, and cellulose was 25:30:50. Due to the high content of thermoplastic copolymer in the formula, the product prepared by applying it to umbilical patch had insufficient viscosity, poor adhesion, and was easy to fall off.

[0098] In Comparative Example 3, the mass ratio of thermoplastic copolymer, tackifying resin, and cellulose was 10:15:20. Due to the low content of tackifying resin in the formulation, the product prepared by applying it to the umbilical patch had insufficient viscosity, poor adhesion, and was easy to fall off.

[0099] In Comparative Example 4, the mass ratio of thermoplastic copolymer, tackifying resin, and cellulose was 20:35:50. Due to the high content of tackifying resin in the formulation, the product prepared by applying it to the umbilical patch had good adhesion, but strong peeling force and strong pain.

[0100] In Comparative Example 5, the mass ratio of thermoplastic copolymer, tackifying resin and cellulose was 10:20:15. Due to the low content of cellulose in the formula, the product prepared by applying it to the umbilical patch had good initial adhesion but poor later adhesion, strong peel force and poor sweat resistance.

[0101] In Comparative Example 6, the mass ratio of thermoplastic copolymer, tackifying resin and cellulose was 20:30:55. Due to the high content of cellulose in the formula, the product prepared by applying it to the umbilical patch had slightly weaker adhesion, weaker peel force and was drier.

[0102] As can be seen from the above experiments, only when the mass ratio of "thermoplastic copolymer, tackifying resin and cellulose" in this application is 10-20:20-30:20-50, the hot melt adhesive for preparing the baby umbilical patch has good adhesion and appropriate peel force at 35-40°C. The implementation method outside the above mass ratio range cannot achieve the corresponding technical effect.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hot melt adhesive for infant umbilical cord dressings, characterized in that, The hot melt adhesive is mainly prepared from thermoplastic copolymers, mineral oil, tackifying resins, cellulose, anti-inflammatory substances, and antioxidants, wherein: The mass ratio of the thermoplastic copolymer, the tackifying resin, and the cellulose is 10~20:20~30:20~50; The hot melt adhesive comprises, by weight parts: Thermoplastic copolymer 10-20 parts, mineral oil 5-10 parts, tackifying resin 20-30 parts, cellulose 20-50 parts, anti-inflammatory substance 1-10 parts, antioxidant 0.1-0.5 parts; The thermoplastic copolymer is obtained by compounding a styrene-isoprene block copolymer with a hydrogenated styrene-butadiene block copolymer; The tackifying resin is C5 or C9 petroleum resin; The cellulose is at least one of methylcellulose, hydroxypropyl methylcellulose, hydroxyethylcellulose, and carboxymethylcellulose; The anti-inflammatory substance is a zinc phosphate silver-loaded inorganic antibacterial powder.

2. The hot melt adhesive for infant umbilical cord dressing according to claim 1, characterized in that, The weight ratio of the styrene-isoprene block copolymer to the hydrogenated styrene-butadiene block copolymer is 10~15:

5.

3. The hot melt adhesive for infant umbilical cord dressing according to claim 1, characterized in that, The mineral oil is a naphthenic oil or white mineral oil; The antioxidant is a sterically hindered phenolic antioxidant, specifically BASF's irganox B225 and 2,6-di-tert-butyl antioxidant. 4 One or two of methylphenols.

4. A method for preparing hot melt adhesive for infant umbilical cord patches according to any one of claims 1 to 3, characterized in that, The preparation method includes: (A) A portion of the tackifying resin is heated and melted with mineral oil and antioxidants to obtain intermediate A; (B) Add a thermoplastic copolymer to intermediate A and heat and stir until melted. Then add the remaining tackifying resin and heat and stir until melted. Then add cellulose and anti-inflammatory substances and heat and stir until melted to obtain intermediate B. (C) Cool intermediate B to obtain hot melt adhesive for infant umbilical cord patches; The heating and melting temperature in step (A) is 140~145℃; In step (B), the temperature for heating and stirring until melting is 140~145℃.

5. The method for preparing hot melt adhesive for infant umbilical cord patches according to claim 4, characterized in that, The tackifying resin in step (A) accounts for 40% of the total mass of the tackifying resin; The tackifying resin added in step (B) is 60% of the total mass of the tackifying resin; Step (B) is carried out under negative pressure evacuation conditions.

6. An infant umbilical patch, characterized in that, The infant umbilical patch includes a backing layer and a sol layer; The sol layer is mainly prepared from the hot melt adhesive for infant umbilical cord patch as described in any one of claims 1 to 3.

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